a9cb2dc1b8
Decoding H264 using Video Decode Acceleration used the custom 'vda_h264_dec'
decoder in FFmpeg.
The Good: This new implementation has some advantages over the previous one:
- It works with Libav: vda_h264_dec never got into Libav since they prefer
client applications to use the hwaccel API.
- It is way more efficient: in my tests this implementation yields a
reduction of CPU usage of roughly ~50% compared to using `vda_h264_dec` and
~65-75% compared to h264 software decoding. This is mainly because
`vo_corevideo` was adapted to perform direct rendering of the
`CVPixelBufferRefs` created by the Video Decode Acceleration API Framework.
The Bad:
- `vo_corevideo` is required to use VDA decoding acceleration.
- only works with versions of ffmpeg/libav new enough (needs reference
refcounting). That is FFmpeg 2.0+ and Libav's git master currently.
The Ugly: VDA was hardcoded to use UYVY (2vuy) for the uploaded video texture.
One one end this makes the code simple since Apple's OpenGL implementation
actually supports this out of the box. It would be nice to support other
output image formats and choose the best format depending on the input, or at
least making it configurable. My tests indicate that CPU usage actually
increases with a 420p IMGFMT output which is not what I would have expected.
NOTE: There is a small memory leak with old versions of FFmpeg and with Libav
since the CVPixelBufferRef is not automatically released when the AVFrame is
deallocated. This can cause leaks inside libavcodec for decoded frames that
are discarded before mpv wraps them inside a refcounted mp_image (this only
happens on seeks).
For frames that enter mpv's refcounting facilities, this is not a problem
since we rewrap the CVPixelBufferRef in our mp_image that properly forwards
CVPixelBufferRetain/CvPixelBufferRelease calls to the underying
CVPixelBufferRef.
So, for FFmpeg use something more recent than `b3d63995` for Libav the patch
was posted to the dev ML in July and in review since, apparently, the proposed
fix is rather hacky.
|
||
|---|---|---|
| audio | ||
| compat | ||
| demux | ||
| DOCS | ||
| etc | ||
| mpvcore | ||
| osdep | ||
| stream | ||
| sub | ||
| TOOLS | ||
| video | ||
| .gitignore | ||
| .travis.yml | ||
| AUTHORS | ||
| configure | ||
| Copyright | ||
| LICENSE | ||
| Makefile | ||
| README.md | ||
| talloc.c | ||
| talloc.h | ||
| travis-deps | ||
| version.sh | ||
mpv
Overview
mpv is a movie player based on MPlayer and mplayer2. It supports a wide variety of video file formats, audio and video codecs, and subtitle types.
If you are wondering what's different from mplayer2 and MPlayer you can read more about the changes.
Compilation
Compiling with full features requires development files for several
external libraries. Below is a list of some important requirements. For
more information see the output of ./configure --help for a list of options,
or look at the list of enabled and disabled features printed after running
./configure. If you think you have support for some feature installed
but configure fails to detect it, the file config.log may contain
information about the reasons for the failure.
Essential dependencies (incomplete list):
- gcc or clang
- X development headers (xlib, X extensions, libvdpau, libGL, libXv, ...)
- Audio output development headers (libasound, pulseaudio)
- fribidi, freetype, fontconfig development headers (for libass)
- libass
- FFmpeg libraries (libavutil libavcodec libavformat libswscale libpostproc)
- libjpeg
- libquvi if you want to play Youtube videos directly
- libx264/libmp3lame/libfdk-aac if you want to use encoding (has to be explicitly enabled when compiling ffmpeg)
Most of the above libraries are available in suitable versions on normal Linux distributions. However FFmpeg is an exception (distro versions may be too old to work at all or work well). For that reason you may want to use the separately available build wrapper (mpv-build) that first compiles FFmpeg libraries and libass, and then compiles the player statically linked against those.
If you are running Mac OSX and using homebrew we provide homebrew-mpv, an up to date formula that compiles mpv with sensible dependencies and defaults for OSX.
configure --enable-* parameters
The --enable-* parameters unconditionally force options on, completely skipping autodetection. This behavior is unlike what you may be used to from autoconf-based configure scripts that can decide to override you. This greater level of control comes at a price. You may have to provide the correct compiler and linker flags yourself. If you used one of these options and experience a compilation or linking failure, make sure you have passed the necessary compiler/linker flags to configure.
Bug reports
Please use the issue tracker provided by GitHub to send us bug reports or feature requests.
Contributing
For small changes you can just send us pull requests through GitHub. For bigger changes come and talk to us on IRC before you start working on them. It will make code review easier for both parties later on.
Contacts
You can find us on IRC in #mpv-player on irc.freenode.net